Disclosed is a device for detecting wall abrasion of a solid-filling feeding well and a detection method thereof. The device comprises a well wall abrasion detector, a horizontal displacement meter, a vertical displacement monitor, and a limit guide rod. One end of the limit guide rod is connected to the well wall abrasion detector. The signal output terminal of the well wall abrasion detector is connected to the signal input terminal of the horizontal displacement meter, and the other end of the limit guide rod passes through the vertical displacement monitor for slidable setting. This disclosure mainly utilizes a resistance strain displacement sensor to detect the abrasion and deformation degree of the well wall, determines the position of damages with the vertical displacement monitor, and draws wall abrasion curves by using the obtained data. The device provided is easy to use, has low cost, has high reliability, and can effectively detect the wall abrasion condition of a solid-filling feeding well, thereby providing a basis for ensuring the working efficiency of the feeding well.

An I-patterned filling method for an initial stage of coal mining based on roof fracture characteristics is provided. A relationship between an overburden load borne by a main roof and an overhang size is determined based on principle of virtual work and a surgery theory when an overhang distance of the main roof reaches an initial weighting interval to enter a plastic limit state with an advance of a working face to obtain the initial weighting interval. An initial fracturing interval of an immediate roof is obtained in the same way. According to a subsidence law of the main roof in an inverted hip roof form, the filling is performed at a key position around an internal plastic hinge line through I-patterned three-strip filling. Size parameters of the I-pattered filling are designed to prevent the immediate roof and the main roof from being fractured.

Disclosed is a method for remining a residual coal pillar in a residual mining area by collaboration of pillar-side backfilling and in-situ gasification. The method includes the following steps of: ascertaining geological and hydrological conditions, a geometric shape and a reserve of a residual coal pillar; determining the feasibility of underground gasification mining for the residual coal pillar; carrying out side supporting on the residual coal pillar in a goaf by using a pillar-side backfilling method; and carrying out the underground gasification mining on the residual coal pillar by means of an underground coal gasification process.

Disclosed is a method for remining a residual coal pillar in a residual mining area by collaboration of pillar-side backfilling and in-situ gasification. The method includes the following steps of: ascertaining geological and hydrological conditions, a geometric shape and a reserve of a residual coal pillar; determining the feasibility of underground gasification mining for the residual coal pillar; carrying out side supporting on the residual coal pillar in a goaf by using a pillar-side backfilling method; and carrying out the underground gasification mining on the residual coal pillar by means of an underground coal gasification process.

A method and an apparatus for creating a void, low-density fill or combination of void and low-density fill for underground mining having at least one module of formwork to be positioned in an open slope of an underground mine prior to carrying out a backfilling operation.

Disclosed is a parallel digging, mining and filling operation coal mining method, in which a stope haulage roadway, stope branch roadways, and two-winged adits are arranged in a stope. The stope haulage roadway and the stope branch roadways serve as haulage passages, and coal mining work is carried out in the two-winged adits. All two-winged adits are mined sequentially and filled timely, and coal mass that has not been mined or two-winged adits that have been filled always exist at the two sides of the two-winged adit that are being mined, to support and control the roof. The two-winged adits can be mined without support or with less supports by controlling the length of the two-winged adits and the number of two-winged adits filled in one time, whereupon pillar-free mining can be realized.

Disclosed is a parallel digging, mining and filling operation coal mining method, in which a stope haulage roadway, stope branch roadways, and two-winged adits are arranged in a stope. The stope haulage roadway and the stope branch roadways serve as haulage passages, and coal mining work is carried out in the two-winged adits. All two-winged adits are mined sequentially and filled timely, and coal mass that has not been mined or two-winged adits that have been filled always exist at the two sides of the two-winged adit that are being mined, to support and control the roof. The two-winged adits can be mined without support or with less supports by controlling the length of the two-winged adits and the number of two-winged adits filled in one time, whereupon pillar-free mining can be realized.

A transportation main roadway and stope branch roadways are arranged by adopting a wangeviry coal mining method. A plurality of stope branch roadways are divided into multiple mining stages, based on which the stope branch roadways are skip-mined; and coal pillars are not reserved among the stope branch roadways. The transportation main roadway is a main transportation channel, and the stope branch roadways are coal mining roadways. All the stope branch roadways are sequentially stoped in a skip-mining manner according to the designed mining sequence and are sequentially and timely filled. The coal never stoped or the filled stope branch roadways is/are used as supports for controlling roofs at the two sides of the stope branch roadways, and the stope branch roadways are sequentially stoped according to a plurality of mining stages, and finally the coal pillar-free mining is realized.

A transportation main roadway and stope branch roadways are arranged by adopting a wangeviry coal mining method. A plurality of stope branch roadways are divided into multiple mining stages, based on which the stope branch roadways are skip-mined; and coal pillars are not reserved among the stope branch roadways. The transportation main roadway is a main transportation channel, and the stope branch roadways are coal mining roadways. All the stope branch roadways are sequentially stoped in a skip-mining manner according to the designed mining sequence and are sequentially and timely filled. The coal never stoped or the filled stope branch roadways is/are used as supports for controlling roofs at the two sides of the stope branch roadways, and the stope branch roadways are sequentially stoped according to a plurality of mining stages, and finally the coal pillar-free mining is realized.

The present invention provides for a compressible grout mix for filling an annular gap between a tunnel rock wall surface and a tunnel liner of a tunnel in a rock formation subject to time dependent deformation after excavation and a method of filling the annular gap between a tunnel rock wall surface and a tunnel liner of a tunnel in a rock formation subject to time dependent deformation after excavation utilizing the compressible grout mix for resilient absorption of forces in the hardened state of the compressible grout mix exerted by the time dependent deformation of the rock wall surface into the tunnel opening. The method includes:

a. providing the compressible grout mix comprising hydraulic binding agent, bentonite clay, polymer foam particles, water-reducing admixture, water and air,
b. placing the compressible grout mix in the annular gap between the tunnel wall rock surface and the tunnel liner, and
c. allowing the compressible grout mix to set, wherein the compressible grout mix in the hardened state has a compressible ratio greater than the anticipated time dependent deformation.